The effects of methylphenidate on reading achievement are studied in children receiving a dual diagnosis of attention deficit disorder with hyperactivity and developmental reading disorder. Children between the ages of seven and one-half and ten and one-half years are matched in groups of three on IQ, age, sex, and reading level. One member from each triad is assigned randomly to each of the three treatment groups: placebo, 0.3 milligrams/kilogram and 0.7 milligrams/kilogram. All children receive structured reading remediation during a six month program. Plasma levels are determined, and measures of reading achievement, instructional process, social behavior, and laboratory learning are obtained.